Astronomy: Puzzling Pulsars

The more that astronomers learn about
pulsars, the still-to-be-identified bodies that are sending strange
beeping signals from the Milky Way, the more difficult to identify the
pulsars become.
Last week, at a Manhattan gathering of the growing group of pulsar
specialists, scientists from the Kitt Peak National Observatory in
Arizona and the Lick Observatory in California disclosed that Pulsar I
not only sends out high-frequency radio signals every 1.3 seconds, but
also gives off light flashes just about half as often. The conferees
were beginning to ponder this new information when...